Fate of Toxic Organic Compounds in Activated Sludge and Integrated PAC Systems

1987 ◽  
Vol 19 (3-4) ◽  
pp. 471-482 ◽  
Author(s):  
W. J. Weber ◽  
B. E. Jones ◽  
L. E. Katz

The addition of powdered activated carbon (PAC) to activated sludge treatment systems to enhance removal of specific toxic organic compounds from wastewater was evaluated. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studied. Kate and equilibrium investigations were conducted to quantify the removal mechanisms of volatilization, biodegradation, biosorption, and carbon adsorption. Results from steady-state bioreactor studies showed that the addition of less than 100 mg/ℓ powdered activated carbon to the influent did not enhance the removal of the biodegradable target compounds investigated: benzene, toluene, ethylbenzene, o-xylene, chlorobenzene, and nitrobenzene. Significantly improved removals of the poorly degradable and non-biodegradable compounds 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and lindane occurred at influent powdered carbon concentrations in the 12.5 to 25 mg/ℓ range. Influent powdered carbon concentrations of 100 mg/ℓ effected overall removals of greater than 90%. The addition of powdered activated carbon not only reduced effluent concentrations but also reduced the amounts of the volatile compounds stripped to the atmosphere.

2007 ◽  
Vol 7 (5-6) ◽  
pp. 43-51 ◽  
Author(s):  
Y. Matsui ◽  
T. Aizawa ◽  
M. Suzuki ◽  
Y. Kawase

The musty-earthy taste and odour caused by the presence of geosmin and other compounds in tap water are major causes of consumer complaints. Although ozonation and granular activated carbon (GAC) adsorption have been practiced in water-treatment plants to remove these compounds effectively, two major problems associated with the application of these processes – formation of stringently regulated bromate ions by ozonation and unhygienic invertebrate colonisation of GAC filters – are still to be resolved. This research advanced the process of adsorption by powdered activated carbon (PAC) by reducing its particle size to the submicrometre range for microfiltration pretreatment. Adsorption pretreatment by using this super (S)-PAC removed the geosmin with vastly greater efficiency than by normal PAC. Removal was attained in a much shorter contact time and at a much lower dosage. The S-PAC was also beneficial in attenuating the transmembrane pressure rises that occurred between both physical backwashings and chemical cleanings.


2000 ◽  
Vol 41 (1) ◽  
pp. 231-235 ◽  
Author(s):  
R.M. Ramíirez Zamora ◽  
A. Durán Moreno ◽  
M.T. Ortade Velásquez ◽  
I. Monje Ramírez

This work compares two pre-treatments (coagulation-flocculation process (CF) and the Fenton oxidation Method (FE)) of the activated carbon adsorption process (AC) to optimize the removal of the organic compounds in landfill leachates. The content of organic compounds was measured in terms of three global parameters: colour, chemical oxygen demand (COD) and dissolved organic carbon (DOC). The result obtained in discontinuous reactor conditions showed an increase in colour removal from 1.5 to 2.0 times and a decrease of COD between 0.3 to 0.5 times for the FE-AC treatment, in relation to the CF-AC treatment. On the other hand, the data obtained in continuous reactor conditions (packed columns) showed that the column fed with leachate CF exhibited operation times 1.3 times longer and a better physiochemical quality in the filtrate (COD and colour) than the one fed with the FE leachate. Nevertheless, the adsorption capacities in the colour removal column of COD and DOC were higher for the FE leachate.


2011 ◽  
Vol 287-290 ◽  
pp. 2070-2073
Author(s):  
Jun Tan Liu ◽  
Shi Jing Liu ◽  
Huan Gao

This research focuses on absorption of Cr(VI) in wastewater by powdered activated carbon, and determines the effect of pH, initial concentration of solution, amount of powdered activated carbon, adsorption time, adsorption temperature, etc, on adsorption of Cr(VI) in wastewater. The results show that the treatment of 100mL containing Cr(VI) wastewater with concentration of 50mg/L will work best in the conditions of 0.35g powdered activated carbon, pH=3.0, 298K, and 1hour oscillatory adsorption.


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